Tagāti Book G, Graphite and TeXLive 2014

I updated my operating system to Ubuntu 15.04 ‘Vivid’ the other day and ran into trouble when I tried using my Tahano Hikamu font, Tagāti Book G. The issue was that XeLaTeX would ignore Graphite as the text rendering engine for this font in spite of my explicitly declaring it:

\newfontfamily{\Tagati}[
    Renderer=Graphite,
    ...
]{Tagati Book G}

The result was that none of the diacritics were aligned correctly, since the font is not configured for OpenType to handle them:

Demonstration of the bug in fontspec-xetex.sty 2.4a
a: Rendering as expected; b: Graphite ignored

After some research, it turned out that the bug is with the file fontspec-xetex.sty.[1. On my system, the path to the file is /usr/share/texlive/texmf-dist/tex/latex/fontspec/fontspec-xetex.sty, use kpsewhere fontspec-xetex.sty to find it, otherwise.] Ubuntu 15.04 still ships with TeXLive 2014, which includes version 2.4a of it as a part of the fontspec package. In this version, there is a typo in the definition for Graphite which apparently makes it inaccessible through the Renderer option. You can read up on it in the bug report on GitHub.

Changing fontspec-xetex.sty according to the bug report and saving it under my home directory’s TeX tree at ~/texmf/tex/latex/fontspec/ to not overwrite the original file solved the issue for me. Another way to solve the issue for the time being is to include a snippet of code in your TeX file’s preamble that basically redefines the respective function.

The issue is already fixed in the latest version of the fontspec package, also in the version that’s available from CTAN, so I hope there will be an update to the fontspec package in the official Ubuntu repositories as well sometime.